Recently AustStab were asked to provide information about the benefits and risks of sidecasting materials.
Sidecasting is the removal of the top layer of material, for example the top 200m of material, to allow stabilisation of the lower layer with a cementious binder. This is following by replacing the top layer together with the uppermost 50mm of the lower layer in the final phase.
There is limited performance data available on multi-layered stabilised pavement processes and the risks inherent in it are:
- Good mixing depth control is required:
- Where significant delay occurs between the placement of the upper and lower layers, and shrinkage cracking in the upper layer may terminate at the interface of the bound layers. This may result in the ingress of moisture to (and laterally along) the interface and may cause localised debonding.
More information is available in the AustStab Pavement Recycling and Stabilisation Guide.